Building an ADU to Rent in Coronado

Yes, you can build an accessory dwelling unit (ADU) on a Coronado residential lot and rent it out, but not short term: state law requires ADU rentals to be for a term longer than 30 days, Coronado's codified rule still says six months, and the city's ADU rules are about to change. Coronado's ADU ordinance (Coronado Municipal Code § 86.56.105) has been amended by Ordinance 2026-08, which takes effect November 5, 2026, and its text was not yet available when this guide was written. Use the rules below to plan, then confirm the current rules with Coronado Community Development before you pay for a design.

Key takeaways

• State law requires any rental of an ADU or junior ADU (JADU) to be for a term longer than 30 days (Gov. Code §§ 66323(e), 66333(g), as of October 2026).
• Coronado's codified ADU section still says six consecutive months or more. The state housing department told the city in December 2025 that this exceeds state law, and the city's amendment takes effect November 5, 2026.
• Under the codified Coronado rules, an ADU can be up to 850 square feet (studio or one bedroom) or 1,000 square feet (more than one bedroom), and a new detached ADU is generally limited to 16 feet in height.
• An ADU can't be sold separately from the main house, and a JADU that shares bathroom facilities with the main house carries an owner-occupancy requirement.
• Review is ministerial, with no public hearing, and the code calls for a decision within 60 days of a complete application.

The ADU rules are changing on November 5, 2026

Here is the timeline, as of October 19, 2026:

1. April 16, 2024: Coronado adopted Ordinance 2024-02, the version of CMC § 86.56.105 that is codified today.
2. December 10, 2025: the California Department of Housing and Community Development (HCD) sent the city a review letter (opens in a new tab) finding the ordinance out of step with state ADU law in several respects, including the six-month rental term.
3. October 6, 2026: the date of Ordinance 2026-08, which amends subsections (A), (B), (C) and (E) of § 86.56.105.
4. November 5, 2026: Ordinance 2026-08 takes effect.

We could not read the text of Ordinance 2026-08, so this guide does not say what it changes. Every Coronado-specific number below is the codified rule that applies until November 5, 2026, and any of them may be different after that date. Before you hire a designer, ask Coronado Community Development which version of § 86.56.105 will govern your application. The code also says that where any part of the section conflicts with state law, state law controls (§ 86.56.105(G)).

What state law sets for every California ADU

California's ADU statutes were renumbered in 2024 (SB 477) and now sit at Government Code §§ 66310 to 66342. The parts that matter most to a landlord:

• Rental term. A city must require that an ADU rental be "for a term longer than 30 days" (Gov. Code § 66323(e), amended effective January 1, 2026), and the same rule applies to JADUs (§ 66333(g)). A city may require rentals of 30 days or longer, but may not impose additional standards beyond those the statute lists, "including an owner-occupant requirement" (§ 66315).
• Owner occupancy for JADUs. As of January 1, 2026 (AB 1154), owner occupancy can be required only for a JADU that shares sanitation facilities with the main home (§ 66333(b)).

Read the rental-term rule in Gov. Code § 66323 (opens in a new tab).

Coronado's codified ADU rules (in effect until November 5, 2026)

These come from CMC § 86.56.105 (opens in a new tab) as codified through Ordinance 2024-02. Treat them as a planning starting point, not a final answer.

Two notes on that table. The parking rules rest on Coronado lying entirely within the Coastal Zone, and HCD's letter reviewed them separately, so don't treat them as settled. The code also requires a covenant, recorded with the County Recorder before the building permit is issued, that tells future owners about owner-occupancy rules, the ban on separate sale, the unit's approved size and the minimum rental period (§ 86.56.105(F)).

Renting the ADU: what changes for you as a landlord

Minimum stays

An ADU in a residential zone is still subject to Coronado's general short-term rental ban: no dwelling or habitable unit in a residential zone may be rented for 25 consecutive days or fewer (CMC § 86.78). The state's "longer than 30 days" ADU rule is stricter than that. Coronado's code has historically required six months; the state told the city in December 2025 that this exceeds what state law allows, and the city's amendment takes effect November 5, 2026. Check current city rules before you sign a lease. Our guide to Coronado short-term rental rules covers the wider picture.

Only a permitted ADU can be rented separately

Coronado bars renting an accessory building, or living space inside one, independently of the main house unless it is a permitted ADU under § 86.56.105 (CMC § 86.56.100(H)). A converted garage or guest house without ADU approval can't be leased on its own.

Owner occupancy

The codified Coronado section requires one dwelling on a JADU lot to be the principal residence of at least one legal owner, backed by a recorded covenant. It contains no owner-occupancy rule for a regular ADU. Under state law effective January 1, 2026, that JADU requirement can apply only where the JADU shares sanitation facilities with the main home. If you plan to rent both the house and the unit, a regular ADU, or a JADU with its own bathroom, is the configuration to discuss with the city.

Lease and safety basics still apply

An ADU tenancy is a residential tenancy. The same rules apply as for the main house: smoke alarms, a carbon monoxide device where there is a fuel-burning appliance, fireplace or attached garage, a working stove and refrigerator for leases entered into, amended or extended on or after January 1, 2026 (Civ. Code § 1941.1), and the one-month security deposit cap (Civ. Code § 1950.5). If you know the gas or electric meter for a tenant's unit also serves areas outside that unit (for example, the ADU meter also serves the main house), you must disclose that before the tenancy begins and put the payment arrangement in writing (Civ. Code § 1940.9). See California landlord laws for Coronado owners for the full list.

HOA, business certificate and rent cap

• HOA. Association rules may not prohibit or unreasonably restrict renting an ADU or JADU, and an ADU is not counted as a separate interest (Civ. Code § 4741).
• City business certificate. Coronado exempts owners renting two or fewer residential dwelling units (CMC § 13.10.030(C)). Owners renting three or more residential units fall under the business certificate rules, so ask the city how it counts a main house plus an ADU if you rent other units too.
• Rent cap. Housing issued a certificate of occupancy within the previous 15 years is exempt from the state rent cap (Civ. Code § 1947.12(d)(4)). Ask your attorney how that applies to a newly built ADU on an older lot.

Taxes and historic lots

Completed new construction is one of the events that triggers a property tax reassessment in California, so expect the county assessor to value the new unit (BOE Publication 29). Renting alone does not trigger reassessment. On your federal return, rental income and expenses go on Schedule E, residential rental buildings are depreciated over 27.5 years, and land is not depreciable (IRS Pub 527). Our guide to Coronado rental taxes goes further.

If your home is a designated historic resource or in a historic district, the separate two-unit (SB 9) process is not available (CMC § 86.56.180). See renting out a historic Coronado home before you plan exterior changes.

This is general information, not legal or tax advice. Confirm the details for your situation with a California attorney or tax professional.

Frequently asked questions

Can I rent my Coronado ADU on Airbnb?

Not for short stays. Coronado prohibits rentals of 25 consecutive days or fewer in residential zones (CMC § 86.78), and state law requires ADU rentals to be for a term longer than 30 days (Gov. Code § 66323(e)). Coronado's codified ADU section still says six months; that section is being amended effective November 5, 2026, so confirm the current minimum with the city before you sign a lease.

Do I have to live on the property to rent out an ADU in Coronado?

Not for a regular ADU under the codified Coronado section, which has no owner-occupancy rule for ADUs. A JADU is different: the codified rule requires the owner to live in the house or the JADU, and state law since January 1, 2026 limits that requirement to JADUs that share sanitation facilities. Confirm with the city once Ordinance 2026-08 takes effect.

Can I sell the ADU separately from my house?

No. The codified Coronado section says an ADU or JADU may not be owned, sold or otherwise conveyed separately from the primary residence, and a recorded covenant tells future owners about that limit before the building permit is issued.

How long does Coronado take to approve an ADU?

The codified rule makes ADU review ministerial, with no public hearing, and calls for a decision within 60 days of a complete application. Design and construction time come on top of that, and subsection (E), which sets the process, is being amended effective November 5, 2026.

Next step: price the ADU before you build it

Knowing what the finished unit would rent for, and on what lease terms, helps you decide whether it is worth the build. McKee Properties has managed rentals from its Coronado office since 1989; start with our guide to the free Coronado rental analysis, or see how Coronado property management works. More owner guides are in the Coronado Rental Guide.